Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Financial accounting software, Financial Accounting Software An Ide...

Financial Accounting Software An Ideal Accounting Software should have the following features:  Purchase Details  Invoice Details  Purchase/Sale Return (Debit/Cre

Desscribe formation of sperm cells from germ cells, Q. Indicating the name ...

Q. Indicating the name and respective ploidy of each involved cell how can the formation of sperm cells from germ cells be described? The formation of spermatogenesis or sperm

Types of cells in phloem, Types of cells in Phloem The phloem consists...

Types of cells in Phloem The phloem consists of 4 types of cells: i).sieve elements, ii) companion cells, iii) phloem parenchyma and sometimes iv) phloem fibres. The metabolit

What is acetobacter, Q. What is Acetobacter? These bacteria, also known...

Q. What is Acetobacter? These bacteria, also known as "vinegar bacteria", cause significant spoilage in the wine industry but are necessary for vinegar production. The importan

Explain phylum sporozoa, Phylum Sporozoa 1) Thcy do not liavc any exter...

Phylum Sporozoa 1) Thcy do not liavc any external locomotory dcvice and move by wriggling. 2) Reproduction by producing numerous spores. 3) All are parasites of animals,

Morphology of angiosperms, define inflorescence and explain in detail about...

define inflorescence and explain in detail about it''s types

Sterility in angiosperms, Sterility in Angiosperms Sterility in angios...

Sterility in Angiosperms Sterility in angiosperms may arise due to several causes. Either the anther may not be formed, or anthers are formed but meiosis may be abnormal. A

Dissection, a 6th grade student friendly definition?

a 6th grade student friendly definition?

Maintenance of the normal quantity of chromosomes, Q. Why is meiosis signif...

Q. Why is meiosis significant for the maintenance of the normal quantity of chromosomes of a species with sexual reproduction? A reduction to a half of the maximum normal quant

Explain enzyme inhibition, ENZYME INHIBITION Enzymes are often inhibite...

ENZYME INHIBITION Enzymes are often inhibited by  the presence of  suitable inhibitors. Much of current drug therapy  is based  on this. Basically, there  are  three major  cla

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd